SharedPreferences存储和对话框
- SharedPreferences存储
- 对话框
- 后面的几个对话框
- 单选对话框
- 多选对话框
- 等待对话框
- 进度条对话框
- 编辑对话框
- 自定义对话框
SharedPreferences存储
在Android开发中，经常需要将少量简单类型数据保存在本地，如：用户设置。这些需要保存的数据可能一两个字符串，像这样的数据一般选择使用SharedPreferences来保存。
SharedPreferences：一个轻量级的存储类，特别适合用于保存软件配置参数。
（使用xml文件存放数据，文件存放在/data/data//shared_prefs目录下）
使用SharedPreferences存储和读取数据的步骤
存储数据
保存数据一般分为四个步骤：
使用Activity类的getSharedPreferences方法获得SharedPreferences对象；
使用SharedPreferences接口的edit获得SharedPreferences.Editor对象；
通过SharedPreferences.Editor接口的putXXX方法保存key-value对；
通过过SharedPreferences.Editor接口的commit方法保存key-value对。
读取数据
读取数据一般分为两个步骤：
使用Activity类的getSharedPreferences方法获得SharedPreferences对象；
通过SharedPreferences对象的getXXX方法获取数据；
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".MainActivity"
android:orientation="vertical">
<EditText
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:hint="姓名"
android:id="@+id/edtName"/>
<EditText
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:hint="年龄"
android:id="@+id/edtAge"/>
<RadioGroup
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="horizontal">
<RadioButton
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="男"
android:id="@+id/rbtBoy"/>
<RadioButton
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="女"
android:id="@+id/rbtGirl"/>
</RadioGroup>
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="保存"
android:id="@+id/btnSave"/>
</LinearLayout>package com.example.demo;
import androidx.appcompat.app.AppCompatActivity;
import android.content.SharedPreferences;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.RadioButton;
import android.widget.Toast;
public class MainActivity extends AppCompatActivity {
private EditText edtName;
private EditText edtAge;
private RadioButton rbtBoy;
private RadioButton rbtGirl;
private Button btnSave;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
// 初始化组件
initViews();
// 从SP里面读取数据
readFromSP();
// new 空格 CTRL+SHIFT+空格
btnSave.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
String name = edtName.getText().toString();
int age = Integer.parseInt(edtAge.getText().toString());
boolean isBoy = rbtBoy.isChecked();
// 保存数据到SP
writeToSP(name, age, isBoy);
Toast.makeText(MainActivity.this, "保存成功", Toast.LENGTH_SHORT).show();
}
});
}
/**
* 保存个人信息到SP
* @param name 姓名
* @param age 年龄
* @param isBoy 是否男
*/
private void writeToSP(String name, int age, boolean isBoy) {
SharedPreferences personInfo = getSharedPreferences("personInfo", MODE_PRIVATE);
SharedPreferences.Editor edit = personInfo.edit();
edit.putString("name", name);
edit.putInt("age", age);
edit.putBoolean("isBoy", isBoy);
edit.commit();
}
/**
* 初始化组件
*/
private void initViews() {
edtName = findViewById(R.id.edtName);
edtAge = findViewById(R.id.edtAge);
rbtBoy = findViewById(R.id.rbtBoy);
rbtGirl = findViewById(R.id.rbtGirl);
btnSave = findViewById(R.id.btnSave);
}
/**
* 从SP里面读取代码 并显示
*/
private void readFromSP() {
SharedPreferences personInfo = getSharedPreferences("personInfo", MODE_PRIVATE);
String name = personInfo.getString("name", "");
int age = personInfo.getInt("age", 0);
boolean isBoy = personInfo.getBoolean("isBoy", true);
edtName.setText(name);
edtAge.setText(String.valueOf(age));
rbtBoy.setChecked(isBoy);
rbtGirl.setChecked(!isBoy);
}
}对话框
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".MainActivity"
android:orientation="vertical">
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="普通对话框"
android:id="@+id/btn1"/>
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="三个按钮对话框"
android:id="@+id/btn2"/>
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="列表对话框"
android:id="@+id/btn3"/>
</LinearLayout>package com.example.dialog;
import androidx.appcompat.app.AppCompatActivity;
import android.app.AlertDialog;
import android.app.Dialog;
import android.content.DialogInterface;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.Toast;
public class MainActivity extends AppCompatActivity {
private Button btn1;
private Button btn2;
private Button btn3;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
btn1 = findViewById(R.id.btn1);
btn1.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
new AlertDialog.Builder(MainActivity.this)
.setMessage("成绩超过60了吗")
.setTitle("问候")
.setPositiveButton("确定", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
Toast.makeText(MainActivity.this, "恭喜及格",Toast.LENGTH_SHORT).show();
}
})
.setNegativeButton("没有", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
Toast.makeText(MainActivity.this, "遗憾挂科",Toast.LENGTH_SHORT).show();
}
})
.show();
}
});
btn2 = findViewById(R.id.btn2);
btn2.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
new AlertDialog.Builder(MainActivity.this)
.setMessage("你喜欢哪个明星")
.setTitle("请选择")
.setPositiveButton("贾玲", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
Toast.makeText(MainActivity.this, "您选择了贾玲",Toast.LENGTH_SHORT).show();
}
})
.setNegativeButton("沈腾", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
Toast.makeText(MainActivity.this, "您选择了沈腾",Toast.LENGTH_SHORT).show();
}
})
.setNeutralButton("华晨宇", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
Toast.makeText(MainActivity.this, "您选择了华晨宇",Toast.LENGTH_SHORT).show();
}
})
.show();
}
});
btn3 = findViewById(R.id.btn3);
btn3.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
String[] classes = {"19软工1班","19软工2班","19软工3班","19软工4班"};
new AlertDialog.Builder(MainActivity.this)
.setTitle("请选择你在哪个班级")
.setItems(classes, new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
Toast.makeText(MainActivity.this,"您在"+classes[which],
Toast.LENGTH_SHORT).show();
}
})
.show();
}
});
}
}后面的几个对话框
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".MainActivity"
android:orientation="vertical">
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="单选对话框"
android:id="@+id/btn4"/>
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="多选对话框"
android:id="@+id/btn5"/>
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="等待对话框"
android:id="@+id/btn6"/>
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="进度对话框"
android:id="@+id/btn7"/>
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="编辑对话框"
android:id="@+id/btn8"/>
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="自定义对话框"
android:id="@+id/btn9"/>
</LinearLayout>package com.example.demo;
import androidx.appcompat.app.AlertDialog;
import androidx.appcompat.app.AppCompatActivity;
import android.content.DialogInterface;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.Toast;
public class MainActivity extends AppCompatActivity {
private Button btn4;
private Button btn5;
private Button btn6;
private Button btn7;
private Button btn8;
private Button btn9;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
btn4 = findViewById(R.id.btn4);
btn5 = findViewById(R.id.btn5);
btn6 = findViewById(R.id.btn6);
btn7 = findViewById(R.id.btn7);
btn8 = findViewById(R.id.btn8);
btn9 = findViewById(R.id.btn9);
}
}单选对话框
btn4.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
String[] classes = {"19软工1班", "19软工2班", "19软工3班", "19软工4班"};
new AlertDialog.Builder(MainActivity.this)
.setTitle("请选择班级")
.setSingleChoiceItems(classes, -1, new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
Toast.makeText(MainActivity.this, "您来自" + classes[which], Toast.LENGTH_SHORT).show();
// dialog.cancel();
}
})
.setPositiveButton("确定", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
dialog.cancel();
}
})
.show();
}
});多选对话框
btn5.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
String[] likes = {"写代码", "跑步", "音乐", "篮球"};
boolean[] checked = {false, false, false, false};
new AlertDialog.Builder(MainActivity.this)
.setMultiChoiceItems(likes, null, new DialogInterface.OnMultiChoiceClickListener() {
@Override
public void onClick(DialogInterface dialog, int which, boolean isChecked) {
Log.e("MultiChoice", "which = " + which + " isChecked = " + isChecked);
checked[which] = isChecked;
}
})
.setPositiveButton("确定", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
StringBuffer stringBuffer = new StringBuffer();
stringBuffer.append("您的爱好是");
for(int i=0; i<checked.length; i++){
if(checked[i]){
stringBuffer.append(likes[i]).append(",");
}
}
Toast.makeText(MainActivity.this, stringBuffer.toString(), Toast.LENGTH_SHORT).show();
dialog.cancel();
}
})
.show();
}
});等待对话框
btn6.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
ProgressDialog dialog = new ProgressDialog(MainActivity.this);
dialog.setTitle("正在登录...");
dialog.setCancelable(false);
dialog.show();
}
});进度条对话框
btn7.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
ProgressDialog dialog = new ProgressDialog(MainActivity.this);
dialog.setTitle("正在下载。。。");
dialog.setProgressStyle(ProgressDialog.STYLE_HORIZONTAL);
dialog.setMax(100);
dialog.show();
new Thread(new Runnable() {
@Override
public void run() {
int progress = 0;
while(progress <= 100){
progress++;
try {
Thread.sleep(100);
} catch (InterruptedException e) {
e.printStackTrace();
}
dialog.setProgress(progress);
}
dialog.cancel();
}
}).start();
}
});编辑对话框
btn8.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
EditText editText = new EditText(MainActivity.this);
new AlertDialog.Builder(MainActivity.this)
.setTitle("请输入姓名")
.setView(editText)
.setPositiveButton("确定", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
String name = editText.getText().toString();
Toast.makeText(MainActivity.this, "你好"+name,
Toast.LENGTH_SHORT).show();
}
})
.show();
}
});自定义对话框
添加布局文件dialog_layout.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".MainActivity"
android:orientation="vertical">
<EditText
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:id="@+id/edt_name"/>
<EditText
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:id="@+id/edt_age"/>
</LinearLayout>使用布局文件
btn9.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
View view = LayoutInflater.from(MainActivity.this)
.inflate(R.layout.dialog_layout, null, false);
EditText edtName = view.findViewById(R.id.edt_name);
EditText edtAge = view.findViewById(R.id.edt_age);
new AlertDialog.Builder(MainActivity.this)
.setTitle("请输入姓名和年龄")
.setView(view)
.setPositiveButton("确定", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
String name = edtName.getText().toString();
int age = Integer.parseInt(edtAge.getText().toString());
Toast.makeText(MainActivity.this, "你好"+name + "年龄"+ age,
Toast.LENGTH_SHORT).show();
}
})
.show();
}
});
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